Fan frame structure

ABSTRACT

A fan frame structure includes a plastic frame and a metal reinforcing member. The inner side of the frame defines a flow passage for receiving a fan wheel. The metal reinforcing member is joined to the frame intimately. The inner side of the frame is arranged to have a largest diameter so that the flow passage provides more space for accommodating a larger sized fan wheel. Hence, strength of the frame is reinforced, vibration and noise are reduced during a fan wheel running and integral effect of heat dissipation is enhanced largely.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a fan frame structure andparticularly to a fan frame, which provides a plastic frame part and ametal reinforcing member.

2. Brief Description of the Related Art

The fan is an essential part of air cooling radiator device and plays animportant role for heat dissipation effect. The fan is the only movablepart in the radiator device. Meanwhile, noise of the radiator device isinfluenced directly by the running fan. The fan induces air to movethrough the cooling fins with a specific speed and a specific way forheat exchange being performed between the air and the cooling fins suchthat accumulated heat at the cooling fins can be carried away to achieveheat removal with forced convection.

Air flow and air pressure decide a fan being strong or weak. The airflow refers a product of an area of the air passing through and avelocity of the air passing through the area. When the velocity isconstant, the outer diameter of the fan wheel is larger leads to thearea larger and more air flow can be reached. More air flow allows thecool air absorbs more heat so that the moving air can carry with moreheat and effect of heat dissipation is enhanced. The air pressure refersaddition of a static pressure and a dynamic pressure of the air so thatgreater air pressure leads to the fan having stronger air deliveringcapability.

In order to promote the gross effect of heat dissipation, the big sizedfan has been employed to enhance heat dissipation efficiency. However,due to space limitation, not all the cooling systems are able to use thebig sizes fan even if the smaller sized fan is unable to reach theexpect effect of heat dissipation.

The inventor has found that if the inner side of the fan frame, i.e.,the flow passage of air, is increased radially under a condition of thesize of the fan frame being unchanged, that is, the material between theouter side and the inner side becomes thinner. In other words, the airinlet and the air outlet areas can be increased and a bigger size fanwheel can mounted to the inner side for generating more air flow.

Further, the inventor has found that most of the fan frame is made ofplastic and a little portion of the fan frame is made of metal. The fanframe with plastic material is light but the strength thereof becomesweak in case of the fan frame being changed to be thinner. It is easyfor the plastic fan frame being deformed and it is easy for the plasticfan frame to become soft in a high ambient temperature for a long periodof time. Under these circumstances, normal operation of the fan isaffected significantly.

The metal fan frame provides enough strength but it is heavy and easy toproduce louder noise while the air passing the fan frame to hit theinner wall of the fan frame. In addition, the metal fan frame is morecostly than the plastic fan frame and manufacturing process of the metalfan frame is more complicated than the plastic fan frame.

SUMMARY OF THE INVENTION

In order to solve the preceding problems, an object of the presentinvention is to provide a fan frame structure with which the inner sideof the fan frame expands toward the outer side thereof to the most forthe flow passage thereof being able to receive a fan wheel with a biggerdiameter and promoting heat dissipation effect.

Another object of the present invention is to provide a fan framestructure in which the fan frame is composed of a plastic frame part anda metal reinforcing member for strengthening the fan frame and lesseningnoise and vibration.

Accordingly, the fan frame structure according to the present inventionincludes a plastic frame member and a metal reinforcing member. Theframe member has an outer side and an inner side. The inner side of theframe member defines a flow passage for receiving a fan wheel. The metalreinforcing member is joined to the frame intimately. The inner side ofthe frame is arranged to have a largest diameter so that the flowpassage provides more space for accommodating a larger sized fan wheel.Hence, strength of the frame is reinforced, vibration and noise arereduced during a fan wheel running and integral effect of heatdissipation is enhanced largely.

BRIEF DESCRIPTION OF THE DRAWINGS

The detail structure, the applied principle, the function and theeffectiveness of the present invention can be more fully understood withreference to the following description and accompanying drawings, inwhich:

FIG. 1 is a disassembled perspective view of the first embodiment of afan frame according to the present invention;

FIG. 2 is a fragmentary disassembled sectional view of the firstembodiment of a fan frame according to the present invention;

FIG. 3 is a fragmentary assembled sectional view of the first embodimentof a fan frame according to the present invention;

FIG. 4 is a disassembled perspective view of the first embodiment of afan frame according to the present invention illustrating another shapethereof;

FIG. 5 is a disassembled perspective view of the second embodiment of afan frame according to the present invention;

FIG. 6 is a disassembled perspective view of the second embodiment of afan frame according to the present invention illustrating another shapethereof;

FIG. 7 is a disassembled perspective view of the second embodiment of afan frame according to the present invention illustrating a furthershape thereof;

FIG. 8 is a disassembled perspective view of the third embodiment of afan frame according to the present invention illustrating the firstshape thereof;

FIG. 9 is a disassembled perspective view of the third embodiment of afan frame according to the present invention illustrating the secondshape thereof;

FIG. 10 is a disassembled perspective view of the third embodiment of afan frame according to the present invention illustrating the thirdshape thereof;

FIG. 11 is a disassembled perspective view illustrating the first shapeof the third embodiment of a fan frame according to the presentinvention providing ventilating apertures;

FIG. 12 is a disassembled perspective view illustrating the second shapeof the third embodiment of a fan frame according to the presentinvention providing ventilating apertures;

FIG. 13 is a disassembled perspective view illustrating the third shapeof the third embodiment of a fan frame according to the presentinvention providing ventilating apertures;

FIG. 14 is a sectional view of illustrating fan wheels disposed in thefan frame of the first embodiment in series;

FIG. 15 is a diagram illustrating characteristics of the fan with fanframe of the invention and the conventional fan frame via air pressurecurves in terms of flow rate; and

FIG. 16 is a diagram illustrating characteristics of the fan with fanframe of the invention and the conventional fan frame via noise curvesin terms of fan speeds.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 3, the first embodiment of a fan frame accordingto the present invention provides a frame member 11, which is made ofplastics and has an inner frame side 111 and an outer frame side 112.The inner frame side 111 defines a space 113 for receiving a fan wheel12. An inlet 114 and an outlet 115 are formed at two lateral sides ofthe space 113 respectively. The outer frame side 112 defines the size ofthe frame member 11. The frame member 11 has a receiving part 25 foraccommodating a metal reinforcing member 13, which is shaped as stripring, such that once the metal reinforcing member 13 is joined to theframe member 11 tightly, the metal reinforcing member 13 constitutes theinner frame side 111 to face the fan wheel 12 for strengthening theframe member 11.

The plastic frame member 11 provides a gross volume greater than themetal reinforcing member 13. Each of the four sides of the frame member11 provides the shortest distance between the frame inner side 111 andthe frame outer side 112, that is, spots a, b, c, d indicated by anarrow respectively are the shortest distances between the frame innerside 111 and the frame outer side 112 and it means the spots a, b, c,and d are thinnest areas of the frame member 11.

As the foregoing, the metal reinforcing member 13 is disposed at theframe inner side 111 after the plastic frame 11 being joined to themetal reinforcing member 13, that is, the metal reinforcing member 13 isdisposed opposite the fan wheel 12 and the frame inner side 111 iscomposed of the metal member 13.

Referring to FIG. 4, the plastic frame 11 provides two receiving parts26, which are dovetail grooves shown in the figure, at each outer sidethereof. An outer metal casing 14 provides two engaging parts 27, whichare dovetails as shown in the figures, at each of the four inner sidesthereof corresponding to the receiving parts 26. Once the engaging parts27 engage with the receiving parts 26, the outer casing 14 is joined tothe frame 11 tightly to surround the spots a, b, c and d.

Referring to 5, the second embodiment of a fan frame structure accordingto the present invention is illustrated. The entire structure andfunctions of the second embodiment is about the same as the firstembodiment. The difference of the second embodiment from the firstembodiment is in that four corners of the plastic frame member 11 areindependently disposed to space apart from each other with an equaldistance. The four corners connect with a fan wheel seat 119 via aconnecting part 118 respectively and a fan wheel 12 is rotationallyjoined to the seat 119.

The preceding frame member 11 provides a receiving slot 25 at each ofthe four corners without passing through either the inlet 114 or theoutlet 115. The receiving slot 25 shown in FIG. 5 has a non-passingsection without passing through the outlet 115. The metal reinforcingmember 13 provides a recess 132 corresponding to the non-passing sectionof the receiving slot 25. When the metal reinforcing member 13 isinserted into the receiving slot 25 to fit with the frame member 11tightly, the recess 132 is joined to the non-passing section of thereceiving slot 25 respectively. The metal reinforcing member 13constitutes the thinnest spots a, b, c and d of the frame member 11between two of the corners respectively.

Referring to FIG. 6, a pair of metal reinforcing members 13, which areshaped as bent strips, are employed instead of the metal member 13 shownin FIG. 5. One of the metal reinforcing members 13 has the thinnestspots a, b and another metal reinforcing member 13 has the thinnestspots c, d. A pair of diagonal corners of the frame member 11 provides areceiving slot 25 the same as that shown in FIG. 5 and another pair ofdiagonal corners provides two opposite recess steps respectively with aprojection at the bottom of the respective recess step. Each reinforcingmember 13 has a lower cut-out corner at both end sides thereofcorresponding to the projection respectively in addition to having therecess 132 for being inserted into the receiving slot 25. Hence, thecut-out corners fit with the projections while the metal reinforcingmembers 13 mounting to the frame 11. Further, referring to FIG. 7, twopairs of metal reinforcing plates 13, 13 are provided instead of themetal members 13 shown in FIG. 6 with each of the metal reinforcingplates 13 having two cut-out lower corners. The four corners of theframe member 11 provide two opposite recess steps with a projection atthe bottom of the respective recess step corresponding to two of thecut-out corners for the metal reinforcing plates 13 fit with four sidesof the frame 11 to constitute the thinnest spots a, b, c, and drespectively.

Referring to FIGS. 8 to 13, the third embodiment of a fan framestructure according to the present invention is illustrated. The entirestructure and functions of the third embodiment is about the same as thepreceding embodiments. The identical parts are designated the samenumerals and no detail will be described further. The difference of thethird embodiment from the preceding embodiments is in that the metalreinforcing member 13 is disposed between the inlet 114 and the outlet115. The metal reinforcing member 13 shown in FIG. 8 provides a shapethe same as the square plastic frame member 11 and the inlet 14 is at aside of the metal reinforcing member 13. A plurality of receiving parts26, which are locating holes at the four corners of the frame member 11and a plurality of engaging parts 27, which are locating pins, extendingdownward from the bottom of the four corners of the metal reinforcingmember 13 corresponding to the receiving parts 26. Hence, the metalreinforcing member 13 is capable of being joined to the frame 11. Themetal reinforcing member 13 shown in FIG. 9 is arranged with the outlet115 and four corners of the metal member have a plurality of engagingmembers 27, which are locating pins too, and the four corners of theframe provides a plurality of receiving parts 26, which are locatingholes extending inward from the bottom of the frame 11. The metalreinforcing member 13 shown in FIG. 10 is disposed between two plasticframe sections 11. One of the frame sections 11 is arranged with theinlet 114 and the other one of the frame sections 11 is arranged withthe outlet 115. Further, the four corners of the metal reinforcingmember 13 provide a plurality of engaging parts 27, which are locatingpins, at the top and the bottom thereof. The frame sections 11 providereceiving parts 26, which are locating holes, corresponding to theengaging parts 27 respectively for the metal member 13 being capable ofbeing joined to the two frame sections.

Referring to FIGS. 11 to 13, the metal reinforcing member 13 in FIG. 11is similar to that shown in FIG. 8, the metal reinforcing member 13 inFIG. 12 is similar to that shown in FIG. 9 and the metal reinforcingmember 13 shown in FIG. 13 is similar to that shown in FIG. 10. Thedifference of the metal reinforcing member 13 shown in FIGS. 11 to 13respectively from that shown in FIGS. 8 to 10 is in that the metalreinforcing member 13 has a plurality of apertures 131 at the lateralsides thereof for admitting fluid in order to increasing air flow.

Referring to FIG. 14, two fan wheels 12 are arranged in series in theframe 11 instead of single fan wheel 12 in the first embodiment. Ofcourse, it is available for arranging more than two fan wheels 12 inseries in case of enough space is provided in the frame 11.

In addition, the receiving part 25 and the metal reinforcing member 13in the preceding embodiments can be coated with joining bond for themetal member 13 being secured to the receiving part 25 firmly.Alternatively, either the receiving part 25 or the metal reinforcingmember 13 can be arranged at least an accommodating portion and theother one is arranged at least an engaging portion for securing themetal reinforcing member 13 to receiving part 25 firmly.

Furthermore, the metal reinforcing member 13 in the precedingembodiments can be made of high strengthen compound material such aspolymeric fiber and/or carbon fiber and/or plastic fiber and/orcarbon-plastic fiber instead of metal.

Referring to FIG. 15, curve of the air pressure in relation to flow rateis for the fan F1, which provides the fan frame of the presentinvention, and curve of the air pressure in relation to flow rate is forthe fan F2, which provides the conventional fan frame. Due to thediameter of the inner side in the fan frame of the present invention isgreater than that of the conventional fan frame and a bigger sized fanwheel is able to be mounted to the fan frame of the present invention,the air pressure induced by the fan F1 is greater than that induced bythe fan with the conventional fan frame under a condition of the sameflow rate and, by the same token, the air flow of the fan F1 is greaterthan that of the fan with the conventional fan frame under a conditionof the same air pressure. Hence, entire fan characteristics of the fanF1 are much higher than those of the fan F2.

Referring to FIG. 16, curve of noise in relation to fan speed for thefan F1 provides the fan frame of the present invention and curve ofnoise in relation to fan speed for the fan F2 provides the conventionalfan frame. Taking a range of fan speed between 6,000 rpm and 16,000 rpmfor explanation, it can be seen the noise of the fan F1 is between 23dBA and 45 dBA but the noise of the fan F2 is between 26 dBA and 49 dBA.That is, the fan F1 generates lower noise than the fan F2 because of thefan frame of the present invention is composed of a plastic frame and ametal member.

As the foregoing, it is appreciated that comparing to the prior art, thefan frame structure of the application has the following advantages:

1. The plastic frame member 11 is joined to the metal reinforcing member13, which also can be made of compound material, intimately forlessening noise generated from the fluid impacting the frame member 11and diminishing consonant vibrations during the fan wheel 12 running inaddition to intensifying strength thereof.

2. The frame member 11 with the metal reinforcing member 13 or thecompound member provides higher strength such that the inner side 111 ofthe frame member 11 can be arranged to expand radially and outwardlytoward the outer sides 112 to the most to obtain the bigger diameter ofthe inner side 111 than the prior art. In this way, the inlet and outletof the frame member 11 becomes larger and more flow rate and higher airpressure can be obtained. Further, the flow passage 113 surrounded bythe inner side 111 becomes more space for accommodating larger fan wheel12 and increasing the flow rate.

3. The thinnest spots a, b, c and d of the frame member 11 can beobtained once the inner side of the frame member 11 expands radiallytoward the outer sides 112 to the most under support of the metal frame15. Hence, it is capable of overcoming the deficiency of theconventional plastic fan frame providing insufficient strength and beingeasily deformed after being subjected to heat for a long period of time.

4. Due to the volume of the plastic frame member 11 is more than that ofthe metal reinforcing member 13, the entire fan frame of the presentinvention is lighter than the conventional metal fan frame so that notonly the cost of the fan frame can be lowered but also it is capable ofovercoming the problems of noise and vibrations, which the conventionalmetal fan frame is unable to breakthrough.

While the invention has been described with referencing to preferredembodiments thereof, it is to be understood that modifications orvariations may be easily made without departing from the spirit of thisinvention, which is defined by the appended claims.

1. A fan frame structure, comprising: a plastic frame member with aninner side and an outer side, the inner side defining a flow passagewith an inlet and an outlet being disposed at two ends thereof, theouter side defining the size thereof, at least a receiving part beingprovided; and a metal reinforcing member, being joined to the receivingpart intimately; wherein, the inner side is arranged to have a largestdiameter so that the flow passage provides more space for accommodatinga large sized fan wheel; whereby, strength of the frame member isreinforced, vibration and noise are reduced during a fan wheel runningand integral effect of heat dissipation is enhanced largely.
 2. The fanframe structure as defined in claim 1, wherein the receiving part isdisposed at the inner side for the reinforcing member being joined tothe receiving part intimately.
 3. The fan frame structure as defined inclaim 1, wherein the receiving part is disposed at the outer side forthe reinforcing member being joined to the receiving part intimately. 4.The fan frame structure as defined in claim 1, wherein the receivingpart is disposed between the inner side and the outer side for thereinforcing member being joined to the receiving part intimately betweenthe outer side and the inner side.
 5. The fan frame structure as definedin claim 1, wherein the plastic frame provides a volume more than thatof the reinforcing member.
 6. The fan frame structure as defined inclaim 1, wherein the reinforcing member provides a shape of ring plate.7. The fan frame structure as defined in claim 1, wherein thereinforcing member is composed of at least a pair of strip shapedplates.
 8. The fan frame structure as defined in claim 1, wherein atleast a thinnest section is provided at the frame between the outer andinner sides and the reinforcing member is joined to the thinnestsection.
 9. The fan frame structure as defined in claim 1, wherein atleast an engaging recess is provided in the receiving part.
 10. The fanframe structure as defined in claim 10, wherein the reinforcing memberprovides at least an engaging projection corresponding to the engagingrecess.
 11. A fan frame structure, comprising: a plastic frame memberwith an inner side and an outer side, the inner side defining a flowpassage with an inlet and an outlet being disposed at two ends thereof,the outer side defining the size thereof and a plurality of dove tailgrooves being provided at four lateral sections of the outer side ; anda metal reinforcing member with four lateral sides, providing aplurality of dove tail corresponding to the dove tail grooves forengaging with the frame and surrounding the frame. wherein, the innerside is arranged to have a largest diameter so that the flow passageprovides more space for accommodating a large sized fan wheel; whereby,strength of the frame member is reinforced, vibration and noise arereduced during a fan wheel running and integral effect of heatdissipation is enhanced largely.
 12. A fan frame structure, comprising:a plastic frame member with an inner side and an outer side, the innerside defining a flow passage, the outer side defining the size thereofand providing a plurality of engaging holes; and a metal reinforcingmember, providing a shape the same as the frame, having a plurality ofengaging projections corresponding to the engaging holes for beingjoined to each other intimately; wherein, the inner side is arranged tohave a largest diameter so that the flow passage provides more space foraccommodating a large sized fan wheel; whereby, strength of the frame isreinforced, vibration and noise are reduced during a fan wheel runningand integral effect of heat dissipation is enhanced largely.
 13. The fanframe structure as defined in claim 12, wherein the reinforced memberprovides an inlet and the frame provides an outlet.
 14. The fan framestructure as defined in claim 12, wherein the reinforced member providesan outlet and the frame provides an inlet.
 15. The fan frame structureas defined in claim 12, wherein the frame is composed of two frame partswith an inlet at one of the frames and an outlet at the other one offrame parts and the reinforcing member is sandwiched between the frameparts.
 16. The fan frame structure as defined in claim 12, wherein thereinforced member provides a plurality of air apertures at the lateralsides thereof.
 18. The fan frame structure as defined in claim 1,wherein reinforcing member is made of compound material such aspolymeric fiber, carbon fiber, plastic fiber or carbon-plastic fiberinstead.
 19. The fan frame structure as defined in claim 11, whereinreinforcing member is made of compound material such as polymeric fiber,carbon fiber, plastic fiber or carbon-plastic fiber instead.
 20. The fanframe structure as defined in claim 12, wherein reinforcing member ismade of compound material such as polymeric fiber, carbon fiber, plasticfiber or carbon-plastic fiber instead.